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Differences in dissolved cadmium and zinc uptake among stream insects: Mechanistic explanations

Environmental Science and Technology

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DOI: 10.1021/es0404421

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Abstract

This study examined the extent to which dissolved Cd and Zn uptake rates vary in several aquatic insect taxa commonly used as indicators of ecological health. We further attempted to explain the mechanisms underlying observed differences. By comparing dissolved Cd and Zn uptake rates in several aquatic insect species, we demonstrated that species vary widely in these processes. Dissolved uptake rates were not related to gross morphological features such as body size or gill size-features that influence water permeability and therefore have ionoregulatory importance. However, finer morphological features, specifically, the relative numbers of ionoregulatory cells (chloride cells), appeared to be related to dissolved metal uptake rates. This observation was supported by Michaelis-Menten type kinetics experiments, which showed that dissolved Cd uptake rates were driven by the numbers of Cd transporters and not by the affinities of those transporters to Cd. Calcium concentrations in exposure media similarly affected Cd and Zn uptake rates in the caddisfly Hydropsyche californica. Dissolved Cd and Zn uptake rates strongly co-varied among species, suggesting that these metals are transported by similar mechanisms.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Differences in dissolved cadmium and zinc uptake among stream insects: Mechanistic explanations
Series title:
Environmental Science and Technology
DOI:
10.1021/es0404421
Volume
39
Issue:
2
Year Published:
2005
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Science and Technology
First page:
498
Last page:
504
Number of Pages:
7